#!/bin/sh /etc/rc.common
#
# Copyright (C) 2017-2019 Yousong Zhou <yszhou4tech@gmail.com>
#
# This is free software, licensed under the GNU General Public License v3.
# See /LICENSE for more information.
#

USE_PROCD=1
EXTRA_COMMANDS="rules_up rules_down rules_exist"
START=99

ss_confdir=/var/etc/shadowsocks-libev
ss_bindir=/usr/bin

ss_mkjson_server_conf() {
	local cfgserver

	config_get cfgserver "$cfg" server
	[ -n "$cfgserver" ] || return 1
	eval "$(validate_server_section "$cfg" ss_validate_mklocal)"
	validate_server_section "$cfgserver" || return 1
	[ "$disabled" = 0 ] || return 1
	ss_mkjson_server_conf_ "$cfgserver"
}

ss_mkjson_server_conf_() {
	[ -n "$server_port" ] || return 1
	[ -z "$server" ] || json_add_string server "$server"
	json_add_int server_port "$server_port"
	[ -z "$method" ] || json_add_string method "$method"
	[ -z "$key" ] || {
		key="$(echo $key | sed 's/+/-/g; s/\//_/g;')"
		json_add_string key "$key"
	}
	[ -z "$password" ] || json_add_string password "$password"
	[ -z "$password" ] && [ -z "$key" ] && return 1
	[ -z "$plugin" ] || json_add_string plugin "$plugin"
	[ -z "$plugin_opts" ] || json_add_string plugin_opts "$plugin_opts"
	if [ "$obfs" = 1 ]; then
		if [ "$obfs_plugin" = "obfs" ]; then
			obfs_options="obfs=$obfs_type"
			[ -z "$obfs_host" ] || obfs_options="$obfs_options;obfs-host=$obfs_host"
			[ -z "$obfs_uri" ] || obfs_options="$obfs_options;obfs-uri=$obfs_uri"
			[ "$fast_open" = 1 ] && obfs_options="$obfs_options;fast-open"
			[ "$mptcp" = 1 ] && obfs_options="$obfs_options;mptcp"
			[ -z "$timeout" ] || obfs_options="$obfs_options;t=$timeout"
			json_add_string plugin "/usr/bin/obfs-local"
			json_add_string plugin_opts "$obfs_options"
		fi
		if [ "$obfs_plugin" = "v2ray" ]; then
			obfs_options="loglevel=default"
			[ "$obfs_type" = "tls" ] && obfs_options="tls"
			[ -z "$obfs_host" ] || obfs_options="$obfs_options;host=$obfs_host"
			[ -z "$obfs_uri" ] || obfs_options="$obfs_options;path=$obfs_uri"
			[ "$fast_open" = 1 ] && obfs_options="$obfs_options;fast-open"
			json_add_string plugin "/usr/bin/v2ray-plugin"
			json_add_string plugin_opts "$obfs_options"
		fi
	fi
}

ss_mkjson_ss_local_conf() {
	ss_mkjson_server_conf
}

ss_mkjson_ss_redir_conf() {
	ss_mkjson_server_conf
}

ss_mkjson_ss_server_conf() {
	ss_mkjson_server_conf_
}

ss_mkjson_ss_tunnel_conf() {
	ss_mkjson_server_conf || return 1
	[ -n "$tunnel_address" ] || return 1
	json_add_string tunnel_address "$tunnel_address"
}

ss_xxx() {
	local cfg="$1"
	local cfgtype="$2"
	local bin="$ss_bindir/${cfgtype/_/-}"
	local confjson="$ss_confdir/$cfgtype.$cfg.json"

	[ -x "$bin" ] || return
	eval "$("validate_${cfgtype}_section" "$cfg" ss_validate_mklocal)"
	"validate_${cfgtype}_section" "$cfg" || return
	[ "$disabled" = 0 ] || return

	json_init
	ss_mkjson_${cfgtype}_conf || return
	json_add_boolean use_syslog 1
	json_add_boolean ipv6_first "$ipv6_first"
	json_add_boolean fast_open "$fast_open"
	json_add_boolean reuse_port "$reuse_port"
	json_add_boolean no_delay "$no_delay"
	json_add_boolean mptcp "$mptcp"
	[ -z "$local_address" ] || json_add_string local_address "$local_address"
	[ -z "$local_port" ] || json_add_int local_port "$local_port"
	[ -z "$mode" ] || json_add_string mode "$mode"
	[ -z "$mtu" ] || json_add_int mtu "$mtu"
	[ -z "$timeout" ] || json_add_int timeout "$timeout"
	[ -z "$user" ] || json_add_string user "$user"
	json_dump -i >"$confjson"

	procd_open_instance "$cfgtype.$cfg"
	procd_set_param command "$bin" -c "$confjson"
	[ "$verbose" = 0 ] || procd_append_param command -v
	[ -z "$bind_address" ] || procd_append_param command -b "$bind_address"
	procd_set_param file "$confjson"
	procd_set_param limits nofile="512000 512000"
	procd_set_param respawn
	procd_close_instance
	ss_rules_cb
}

ss_rules_restart() {
	local cfg="$1"
	local cfgtype="$2"

	eval "$("validate_${cfgtype}_section" "$cfg" ss_validate_mklocal)"
	"validate_${cfgtype}_section" "$cfg" || return 1
	ss_rules_cb
}

ss_rules_cb() {
	local cfgserver server

	if [ "$cfgtype" = ss_redir ]; then
		config_get cfgserver "$cfg" server
		config_get server "$cfgserver" server
		ss_redir_servers="$ss_redir_servers $server"
		if [ "$mode" = "tcp_only" -o "$mode" = "tcp_and_udp" ]; then
			eval "ss_rules_redir_tcp_$cfg=$local_port"
			eval "ss_rules6_redir_tcp_$cfg=$local_port"
		fi
		if [ "$mode" = "udp_only" -o "$mode" = "tcp_and_udp" ]; then
			eval "ss_rules_redir_udp_$cfg=$local_port"
			eval "ss_rules6_redir_udp_$cfg=$local_port"
		fi
	fi
}

ss_redir_ports() {
	port=$(uci -q get shadowsocks-libev.$1.local_port)
	server=$(uci -q get shadowsocks-libev.$1.server)
	if [ "$server" = "$2" ] || [ "$2" = "" ]; then
		if [ "$port" -lt "$min_ss_redir_ports" ]; then
			min_ss_redir_ports=$port
		fi
		if [ "$port" -gt "$max_ss_redir_ports" ]; then
			max_ss_redir_ports=$port
		fi
	fi
}

ss_rules() {
	local cfg="$1"
	local bin="$ss_bindir/ss-rules"
	local bin6="$ss_bindir/ss-rules6"
	local cfgtype
	local cfgrulesserver
	local local_port_tcp local_port_udp
	local local_port_tcp6 local_port_udp6
	local args
	local rule_name
	if [ "$cfg" = "ss_rules" ]; then
		rule_name="def"
	else
		rule_name="$(echo $cfg | sed 's/_rule//' | cut -c -7)"
	fi

	[ -x "$bin" ] || return 1
	#"$bin" -f
	[ -x "$bin6" ] || return 1
	#"$bin6" -f

	config_get cfgtype "$cfg" TYPE
	[ "$cfgtype" = ss_rules ] || return 1

	config_get cfgrulesserver "$cfg" server

	eval "$(validate_ss_rules_section "$cfg" ss_validate_mklocal)"
	validate_ss_rules_section "$cfg" || return 1
	[ "$disabled" = 0 ] || return 0
	if [ "$ss_rules_redir_tcp_$redir_tcp" = "all" ]; then
		min_ss_redir_ports="65535"
		max_ss_redir_ports="0"
		config_load shadowsocks-libev
		config_foreach ss_redir_ports ss_redir $cfgrulesserver
		if [ "$min_ss_redir_ports" != "$max_ss_redir_ports" ]; then
			all_ss_redir_ports=$min_ss_redir_ports-$max_ss_redir_ports
		else
			all_ss_redir_ports=$min_ss_redir_ports
		fi
		local_port_tcp="$all_ss_redir_ports"
		#local_port_udp="$all_ss_redir_ports"
		eval local_port_udp="\$ss_rules_redir_udp_$redir_udp"
		local_port_tcp6="$all_ss_redir_ports"
		#local_port_udp6="$all_ss_redir_ports"
		eval local_port_udp6="\$ss_rules6_redir_udp_$redir_udp"
	else
		eval local_port_tcp="\$ss_rules_redir_tcp_$redir_tcp"
		eval local_port_udp="\$ss_rules_redir_udp_$redir_udp"
		eval local_port_tcp6="\$ss_rules6_redir_tcp_$redir_tcp"
		eval local_port_udp6="\$ss_rules6_redir_udp_$redir_udp"
	fi
	[ -n "$local_port_tcp" -o -n "$local_port_udp" ] || return 1
	ss_redir_servers4="$(echo "$ss_redir_servers" | grep -o '[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}' | sort -u)"
	ss_redir_servers6="$(echo "$ss_redir_servers" | grep -o '\([0-9a-fA-F]\{0,4\}:\)\{1,7\}[0-9a-fA-F]\{0,4\}' | sort -u)"
	[ -z "$ss_redir_servers4" ] && [ -z "$ss_redir_servers6" ] && {
		ss_redir_servers4="$ss_redir_servers"
		ss_redir_servers6="$ss_redir_servers"
	}
	#ss_redir_servers="$(echo "$ss_redir_servers" | tr ' ' '\n' | sort -u)"
	dst_ips_bypass4="$(echo "$dst_ips_bypass" | grep -o '[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}' | sort -u)"
	dst_ips_forward4="$(echo "$dst_ips_forward" | grep -o '[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}' | sort -u)"
	src_ips_bypass4="$(echo "$src_ips_bypass" | grep -o '[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}' | sort -u)"
	src_ips_forward4="$(echo "$src_ips_forward" | grep -o '[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}' | sort -u)"
	src_ips_checkdst4="$(echo "$src_ips_checkdst" | grep -o '[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}' | sort -u)"
	dst_ips_bypass6="$(echo "$dst_ips_bypass" | grep -o '\([0-9a-fA-F]\{0,4\}:\)\{1,7\}[0-9a-fA-F]\{0,4\}' | sort -u)"
	dst_ips_forward6="$(echo "$dst_ips_forward" | grep -o '\([0-9a-fA-F]\{0,4\}:\)\{1,7\}[0-9a-fA-F]\{0,4\}' | sort -u)"
	src_ips_bypass6="$(echo "$src_ips_bypass" | grep -o '\([0-9a-fA-F]\{0,4\}:\)\{1,7\}[0-9a-fA-F]\{0,4\}' | sort -u)"
	src_ips_forward6="$(echo "$src_ips_forward" | grep -o '\([0-9a-fA-F]\{0,4\}:\)\{1,7\}[0-9a-fA-F]\{0,4\}' | sort -u)"
	src_ips_checkdst6="$(echo "$src_ips_checkdst" | grep -o '\([0-9a-fA-F]\{0,4\}:\)\{1,7\}[0-9a-fA-F]\{0,4\}' | sort -u)"
	[ "$dst_forward_recentrst" = 0 ] || args="$args --dst-forward-recentrst"

	ss_rules_call
	ss_rules_call6
}

ss_rules_call() {
	"$bin" "$@" \
			-s "$ss_redir_servers4" \
			${local_port_tcp:+-l "$local_port_tcp"} \
			${local_port_udp:+-L "$local_port_udp"} \
			${src_default:+--src-default "$src_default"} \
			${dst_default:+--dst-default "$dst_default"} \
			${local_default:+--local-default "$local_default"} \
			${dst_ips_bypass_file:+--dst-bypass-file "$dst_ips_bypass_file"} \
			${dst_ips_forward_file:+--dst-forward-file "$dst_ips_forward_file"} \
			${dst_ips_bypass4:+--dst-bypass "$dst_ips_bypass4"} \
			${dst_ips_forward4:+--dst-forward "$dst_ips_forward4"} \
			${src_ips_bypass4:+--src-bypass "$src_ips_bypass4"} \
			${src_ips_forward4:+--src-forward "$src_ips_forward4"} \
			${src_ips_checkdst4:+--src-checkdst "$src_ips_checkdst4"} \
			${ifnames:+--ifnames "$ifnames"} \
			${ipt_args:+--ipt-extra "$ipt_args"} \
			${cfg:+--rule-name "$rule_name"} \
			$args \
		|| "$bin" "$@" -f
}

ss_rules_call6() {
	"$bin6" "$@" \
			-s "$ss_redir_servers6" \
			${local_port_tcp:+-l "$local_port_tcp6"} \
			${local_port_udp:+-L "$local_port_udp6"} \
			${src_default:+--src-default "$src_default"} \
			${dst_default:+--dst-default "$dst_default"} \
			${local_default:+--local-default "$local_default"} \
			${dst_ips_bypass_file:+--dst-bypass-file "$dst_ips_bypass_file"} \
			${dst_ips_forward_file:+--dst-forward-file "$dst_ips_forward_file"} \
			${dst_ips_bypass6:+--dst-bypass "$dst_ips_bypass6"} \
			${dst_ips_forward6:+--dst-forward "$dst_ips_forward6"} \
			${src_ips_bypass6:+--src-bypass "$src_ips_bypass6"} \
			${src_ips_forward6:+--src-forward "$src_ips_forward6"} \
			${src_ips_checkdst6:+--src-checkdst "$src_ips_checkdst6"} \
			${ifnames:+--ifnames "$ifnames"} \
			${ipt_args:+--ipt-extra "$ipt_args"} \
			${cfg:+--rule-name "$rule_name"} \
			$args \
		|| "$bin6" "$@" -f
}

start_service() {
	local cfgtype

	mkdir -p "$ss_confdir"
	config_load shadowsocks-libev
	for cfgtype in ss_local ss_redir ss_server ss_tunnel; do
		config_foreach ss_xxx "$cfgtype" "$cfgtype"
	done
	# Add rule to match traffic marked by firewall for bypass
	ip rule add prio 1 fwmark 0x539 lookup 991337 > /dev/null 2>&1
	rules_up
}

stop_service() {
	rules_down
	rm -rf "$ss_confdir"
}

rules_exist() {
	[ -n "$(iptables -t nat -L -n | grep ssr)" ] && return 0
	return 1
}

server_state() {
	config_get disabled "$1" disabled "0"
	[ "$disabled" = "0" ] && enabled="1"
	config_get key "$1" key
	[ -n "$key" ] && passkey=$key
	config_get password "$1" password
	[ -n "$password" ] && passkey=$password
}

rules_up() {
	rules_exist && return 0
	[ "$(uci -q get shadowsocks-libev.ss_rules.disabled)" = "1" ] && return 0
	enabled="0"
	passkey=""
	config_load shadowsocks-libev
	config_foreach server_state server
	[ "$enabled" = "0" ] && return
	[ -z "$passkey" ] && return
	logger -t "Shadowsocks" "Rules UP"
	for cfgtype in ss_redir; do
		config_foreach ss_rules_restart "$cfgtype" "$cfgtype"
	done
	config_foreach ss_rules ss_rules
	[ -f /etc/init.d/omr-bypass ] && {
		logger -t "Shadowsocks" "Reload omr-bypass rules"
		/etc/init.d/omr-bypass reload_rules
	}
}

rules_down() {
	rules_exist || return 0
	logger -t "Shadowsocks" "Rules DOWN"
	local bin="$ss_bindir/ss-rules"
	[ -x "$bin" ] && {
		"$bin" -f >/dev/null 2>&1
	}
	local bin6="$ss_bindir/ss-rules6"
	[ -x "$bin6" ] && {
		"$bin6" -f >/dev/null 2>&1
	}
}

service_triggers() {
	procd_add_reload_interface_trigger wan*
	procd_add_reload_trigger shadowsocks-libev
	procd_open_validate
	validate_server_section
	validate_ss_local_section
	validate_ss_redir_section
	validate_ss_rules_section
	validate_ss_server_section
	validate_ss_tunnel_section
	procd_close_validate
}

ss_validate_mklocal() {
	local tuple opts

	shift 2
	for tuple in "$@"; do
		opts="${tuple%%:*} $opts"
	done
	[ -z "$opts" ] || echo "local $opts"
}

ss_validate() {
	uci_validate_section shadowsocks-libev "$@"
}

validate_common_server_options_() {
	local cfgtype="$1"; shift
	local cfg="$1"; shift
	local func="$1"; shift
	local stream_methods='"none", "table", "rc4", "rc4-md5", "aes-128-cfb", "aes-192-cfb", "aes-256-cfb", "aes-128-ctr", "aes-192-ctr", "aes-256-ctr", "bf-cfb", "camellia-128-cfb", "camellia-192-cfb", "camellia-256-cfb", "salsa20", "chacha20", "chacha20-ietf"'
	local aead_methods='"aes-128-gcm", "aes-192-gcm", "aes-256-gcm", "chacha20-ietf-poly1305", "xchacha20-ietf-poly1305"'

	"${func:-ss_validate}" "$cfgtype" "$cfg" "$@" \
		'disabled:bool:0' \
		'server:host' \
		'server_port:port' \
		'password:string' \
		'key:string' \
		"method:or($stream_methods, $aead_methods)" \
		'plugin:string' \
		'plugin_opts:string' \
		'obfs:bool:0' \
		'obfs_plugin:or("v2ray","obfs-simple"):v2ray' \
		'obfs_type:or("http","tls"):http'
}

validate_common_client_options_() {
	validate_common_options_ "$@" \
		'server:uci("shadowsocks-libev", "@server")' \
		'local_address:host:0.0.0.0' \
		'local_port:port'
}

validate_common_options_() {
	local cfgtype="$1"; shift
	local cfg="$1"; shift
	local func="$1"; shift

	"${func:-ss_validate}" "$cfgtype" "$cfg" "$@" \
		'disabled:bool:0' \
		'fast_open:bool:0' \
		'ipv6_first:bool:0' \
		'no_delay:bool:0' \
		'mptcp:bool:0' \
		'reuse_port:bool:0' \
		'verbose:bool:0' \
		'mode:or("tcp_only", "udp_only", "tcp_and_udp"):tcp_only' \
		'mtu:uinteger' \
		'timeout:uinteger' \
		'user:string'
}

validate_server_section() {
	validate_common_server_options_ server "$1" "$2"
}

validate_ss_local_section() {
	validate_common_client_options_ ss_local "$1" "$2"
}

validate_ss_redir_section() {
	validate_common_client_options_ ss_redir "$1" "$2"
}

validate_ss_rules_section() {
	"${2:-ss_validate}" ss_rules "$1" \
		'disabled:bool:0' \
		'redir_tcp:or(uci("shadowsocks-libev", "@ss_redir"),"all")' \
		'redir_udp:or(uci("shadowsocks-libev", "@ss_redir"),"all")' \
		'src_ips_bypass:or(ipaddr,cidr)' \
		'src_ips_forward:or(ipaddr,cidr)' \
		'src_ips_checkdst:or(ipaddr,cidr)' \
		'dst_ips_bypass_file:file' \
		'dst_ips_bypass:or(ipaddr,cidr)' \
		'dst_ips_forward_file:file' \
		'dst_ips_forward:or(ipaddr,cidr)' \
		'src_default:or("bypass", "forward", "checkdst"):checkdst' \
		'dst_default:or("bypass", "forward"):bypass' \
		'local_default:or("bypass", "forward", "checkdst"):bypass' \
		'dst_forward_recentrst:bool:0' \
		'ifnames:maxlength(15)' \
		'ipt_args:string'
}

validate_ss_server_section() {
	validate_common_server_options_ ss_server "$1" \
		validate_common_options_ \
		"$2" \
		'bind_address:ipaddr'
}

validate_ss_tunnel_section() {
	validate_common_client_options_ ss_tunnel "$1" \
		"$2" \
		'tunnel_address:regex(".+\:[0-9]+")'
}
